Paul Harwood, Network Rail’s director of South East route investment, said: “We are working hard to make the least reliable part of our network better for passengers by upgrading the southern end of the Brighton Main Line.

“We are on track to deliver the improvements by next summer but we know there’s never a good time to close the railway, which is why we’re working closely with our train operator partners to provide the best advice so that passengers are inconvenienced as little as possible during our works in November and beyond.”

Network Rail is working to upgrade the track and signalling on the Brighton Mainline, as well as improving drainage to stop flooding inside Victorian tunnels on the line.

Work has taken place at 25 separate sites so far and has included the renewal of 2.7 miles of conductor rail, 532 yards of track and 15 signal heads and the replacement of thousands of tonnes of ballast, engineers said.

November’s work will see the renewal of more track inside the Clayton Tunnel, new signals installed between Patcham and Preston Park and the replacement of electrical circuits between Three Bridges and Balcombe.

Keith Jipps, Govia Thameslink Railway’s infrastructure director, said: “Network Rail’s works to upgrade the Brighton Main Line really are vital for us to improve our service, but we appreciate many of our passengers who use the railway at the weekends are being inconvenienced in the short-term.

“I’d remind travellers in Brighton and surrounding towns that we’re making every effort to keep them open for business with an extensive bus replacement service in place, as well as indirect train routes to and from London and Brighton available via the longer route through Littlehampton.”

The £67m Brighton Main Line Improvement Project is part of a wider £300m programme to improve the reliability of some of the busiest and most congested lines in the south east, including on the recently expanded Thameslink network.

During the closure periods, no trains will run between Three Bridges and Brighton/Lewes via Haywards Heath. Direct services between London and Brighton will continue to run diverted via Littlehampton and Horsham.

A network of replacement bus services will operate for the stations between Three Bridges and Brighton and between Three Bridges and Lewes.